timm/models/layers/linear.py

""" Linear layer (alternate definition)
"""
import torch
import torch.nn.functional as F
from torch import nn as nn


class Linear(nn.Linear):
    r"""Applies a linear transformation to the incoming data: :math:`y = xA^T + b`

    Wraps torch.nn.Linear to support AMP + torchscript usage by manually casting
    weight & bias to input.dtype to work around an issue w/ torch.addmm in this use case.
    """
    def forward(self, input: torch.Tensor) -> torch.Tensor:
        if torch.jit.is_scripting():
            bias = self.bias.to(dtype=input.dtype) if self.bias is not None else None
            return F.linear(input, self.weight.to(dtype=input.dtype), bias=bias)
        else:
            return F.linear(input, self.weight, self.bias)